1. Field of the Invention
The present invention relates to devices for measuring distances between dots of light guide plates (LGPs) of liquid crystal displays (LCDs), and methods for using such devices.
2. Description of the Prior Art
A typical liquid crystal display device comprises an LCD panel, and a backlight system mounted under the LCD panel for supplying light beams thereto. The backlight system mainly comprises a light source and an LGP. The LGP is normally a transparent polymer plate, and is used for guiding light beams emitted by the light source to uniformly illuminate the LCD panel.
A typical LGP has a main light emitting surface, and an opposite bottom surface. The bottom surface has a plurality of dots formed thereon, for diffusing light from the light source.
Conventionally, dimensional parameters such as distances between the dots and a pattern distribution of the dots need to be gauged and verified before the LGP is used, in order to confirm that characteristics of the dots are of satisfactory quality.
Customarily, the dimensional parameters of the dots of the LGP are gauged by a measuring instrument such as a microscope. However, when using such an instrument, there are no reference points for obtaining measurements. Therefore, the dots generally have to be first counted and located in a field of vision before measurements can be obtained. This makes the gauging procedure unduly slow, and there is also the risk of error due to miscounting of the dots.